1. Field of the Disclosure
The present disclosure relates to a trip device of a molded case circuit breaker, and particularly, to a shooter and a crossbar of a molded case circuit breaker.
2. Background of the Disclosure
Generally, a molded case circuit breaker is an electronic device that is provided in a partial region of a power system, and when an abnormal current or overload occurs in electricity, breaks a circuit to protect the circuit and a load device. In the molded case circuit breaker, a circuit is automatically broken by a trip device, and a breaking operation is performed by manually manipulating a handle to an OFF position.
A trip operation of the molded case circuit breaker is described in detail in a trip device of a molded case circuit breaker disclosed in Korean Utility Registration NO. 20-0220198. A trip operation will be briefly summarized with reference to FIG. 1 in the prior art reference.
When an overcurrent occurs on a line, a bimetal 25 is bent to rotate a crossbar 18, a magnetic force is induced to a fixed core 15 which is provided on the line, and a moving core 16 is attracted to the fixed core 15, whereby an end of the moving core 16 hits and rotates the crossbar 18.
The crossbar 18 rotates to release a hanged state of a shooter 20 which is hanged on the crossbar 18. At this time, the shooter 20 rotates with respect to a hinge part 20a with an elastic restoring force of a compressed spring 21, and hits a nail 22 of a mechanism part.
As the nail 22 rotates, a latch holder 24 bound by the nail 22 is released to rotate, a latch 3 engaged with the latch holder 24 rotates, and a lower link 6 and an upper link 4 connected to the latch 3 interoperate with each other to rotate a shaft 8. As the shaft 8 rotates, a movable contactor 10 is detached from a fixed contactor 14, and thus, a flow of a current between a load and a power source is blocked.
In order to re-close the circuit breaker to an electricity conducting state, the circuit breaker is reset by rotating a handle 1 in a closing direction. When the circuit breaker is reset, an end of the handle 1 pushes an inclined surface of the shooter 20, and thus, the shooter 20 rotates with respect to a hinge shaft 20a with a pushing force, and is hanged on the crossbar 18, whereby the circuit breaker is restored to a before-trip state.
The trip device has an action, based on binding and release between a vertical type crossbar and a horizontal type shooter, and an elastic force of a compression spring. Examples of the trip device include a trip device of a molded case circuit breaker disclosed in Korean Utility Registration NO. 20-0218816 and a trip device of a molded case circuit breaker disclosed in Korean Utility Registration NO. 20-0220198.
Unlike such a method, a trip device has been developed in which a crossbar and a shooter are provided in the same direction, and a torsion spring is applied, for increasing an efficiency of a space and performing a stable operation. FIG. 1 illustrates some elements of the trip device using the method. An operation of the trip device will be in more detail with reference to FIG. 1.
A shooter 1 is assembled with a shooter rotating groove 3 of a trip device case 2. In this case, a single torsion spring 4 is assembled with a central shaft 1a of the shooter 1, and enables the shooter 1 to rotate. A crossbar 5 holds the shooter 1 so as to prevent the shooter 1 from springing forth. In detail, a hanging plate 1b of the shooter 1 is bound by a hanger 5a of the crossbar 5. The shooter 1 has a force, which is used to move frontward with an elastic restoring force of the single torsion spring 4, in a state where the shooter 1 is bound to the crossbar 5.
When the crossbar 5 rotates by performing a trip operation and thus a binding force applied to the shooter 1 is released, the shooter 1 rotates forward with the elastic restoring force of the single torsion spring 4, and hits a nail (not shown).
In this case, the elastic restoring force of the single torsion spring 4 is applied to a supporting part 1c which is provided at one side of the shooter 1, and thus, when the shooter 1 rotates, torsion occurs between the trip device case 2 and the shooter 1. The torsion cannot provide a certain force when the hanging plate 1b of the shooter 1 and the hanger 5a of the crossbar 5 operate, and for this reason, the crossbar 5 and the shooter 1 cannot stably operate, and the scattering of load increases.